Top: normalised peak flux densities of 3C 84 measured by three baselines between the GBT and a VLBA station as a function of the distance to the field centre. The blue solid line represents our fit to the data for an Airy disk and the green dashed line for a Gaussian. Bottom: the normalised peak flux densities of 3C 84, after applying the primary beam correction, as a function of the distance to the field centre. The blue solid line represents the mean of the values, which is almost one. The standard deviation is 0.07.